Some example computing systems herein include two modules, e.g., drivers. A first can instantiate an interface associated with a service routine, receive, by the service routine, a verification message; and send, in response, a confirmation message via the interface. A second can locate the interface; open a handle to the interface; send the verification message via the handle, the verification message identifying at least an interface type or a version; and receive, via the handle, the confirmation message associated with the verification message. In some examples, the first driver is a Plug and Play driver. In some examples, the first module can receive, by the service routine, a command associated with the interface; determine that the command is a valid command based at least in part on stored command data; and send, via the interface, a response to the command.